Composition and temperature data from satellite measurements and from radar backscatter observations show that dynamics is a major key in our understanding of the upper atmosphere. Individual gases are tracers of wind fields which in turn are driven by the energy and momentum sources of the complex magnetosphere‐thermosphere‐lower atmosphere system. As is shown with data from Ogo 6, ion drag effects on winds impose a magnetic field control on the thermospheric density structure. Differential heating manifests itself in day‐night and summer‐winter temperature contrasts and drives large‐scale circulation that redistributes the minor gases to account for the observed winter bulges in O and He (a factor of 40 larger in winter than in summer) and the large phase separations between atmospheric species in the diurnal tide. Large‐scale atomic oxygen transport within the thermosphere significantly enhances the annual temperature amplitude (by more than a factor of 2) and, through release of chemical energy, contributes to the mesospheric temperature anomaly. The latter phenomenon and the associated reversals in circulation are largely determined by the annual tide excited near 50 km and possibly by dissipation of gravity and planetary waves in the winter hemisphere. During magnetic storms, Joule heating and viscous dissipation drive winds that effectively deplete O and He in the auroral zones and accumulate them at lower latitudes. Mass transport of O amplifies and confines the temperature enhancement to high latitudes, compatible with the observed global response of mass density. The timing of wind and composition effects significantly contributes to the positive and negative phases in ionospheric storms. Owing to the rotational nature of ion drift momentum sources, their signatures in the atmosphere are comparatively weak and differ substantially from those associated with heat sources.

Gravity waves are prominent in the polar region of the terrestiral thermosphere, and can be excited by perturbations in Joule heating and Lorents force due to magnetospheric processes. We show observations from the Dynamics Explorer-2 satellite to illustrate the complexity of the phenomenon and review the transfer function model (TFM) which has guided our interpretation. On a statistical basis, the observed atmospheric perturbations decrease from the poles toward the equator and tend to correlate with the magnetic activity index, Ap. although individual measurements indicate that the magnetic index is often a poor measure of gravity wave excitation. The theoretical models devised to describe gravity waves are multifaceted. On one end are fully analytical, linear models which are based on the work of Hines. On the other end are fully numerical, thermospheric general circulation models (TGCMs) which incorporate non-linear processes and wave mean flow interactions. The transfer function model (TFM) discussed in this paper is between these two approaches. It is less restrictive than the analytical approach and relates the gIobal propagation of gravity waves to their excitation. Compared with TGCMs, the TFM is simplified by its linear approximation; but it is not limited in spatial and temporal resolution, and the TFM describes the wave propagation through the lower atmosphere. Moreover, the TFM is semianalytical which helps in delineating the wave components. Using expansions in terms of spherical harmonics and Fourier components, the transfer function is obtained from numerical height integration. This is time consuming computationally but needs to be done only once. Once such a transfer function is computed, the wave response to arbitrary source distributions on the globe can then be constructed in very short order. In this review, we discuss some numerical experiments performed with the TFM, to study the various wave components excited in the auroral regions which propagate through the thermosphere and lower atmosphere, and to elucidate the properties of realistic source geometries. The model is applied to the interpretation of satellite measurements. Gravity waves observed in the thermosphere of Venus are also discussed.

Spectral analysis of the midnight temperature anomaly observed on AE‐E indicates that the phenomenon can be adequately represented with wave numbers 1

Objective: The present study describes factors related to fatal abuse in three age groups in the United States Air Force (USAF). Method: Records from 32 substantiated cases of fatal child abuse in the USAF were independently reviewed for 60 predefined factors. Results: Males were over-represented in young child victims (between 1 year and 4 years of age) and child victims (between 4 years and 15 years of age) but not in infant victims (between 24 hours and 1 year of age). African-American infant victims and perpetrators were over-represented. Younger victims were more likely to have been previously physically abused by the perpetrator. Perpetrators were predominantly male and the biological fathers of the victims. Infant and young child perpetrators reported childhood abuse histories, while child perpetrators reported the highest frequency of mental health contact. Victims' families reported significant life stressors. Families of young child victims were more likely divorced, separated, or single. Incidents with infants and young children tended to occur without witnesses; incidents with child victims tended to have the victim's sibling(s) and/or mother present. Fatal incidents were more frequent on the weekend, in the home, and initiated by some family disturbance. Conclusions: Differences among groups in factors related to infant and child homicide across age groups may assist in the development of more tailored abuse prevention efforts and may also guide future investigations.

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